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Keywords = indoor localisation system

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22 pages, 2697 KiB  
Article
Empowering the Irish Energy Transition: Harnessing Sensor Technology for Engagement in an Embedded Living Lab
by Madeleine Lyes
Sustainability 2025, 17(15), 6677; https://doi.org/10.3390/su17156677 - 22 Jul 2025
Viewed by 295
Abstract
The transition to a decarbonised energy system in Ireland presents significant socio-technical challenges. This paper, focused on the work of the SMARTLAB project at the Citizen Innovation Lab in Limerick city, investigated the potential of a localised living lab approach to address these [...] Read more.
The transition to a decarbonised energy system in Ireland presents significant socio-technical challenges. This paper, focused on the work of the SMARTLAB project at the Citizen Innovation Lab in Limerick city, investigated the potential of a localised living lab approach to address these challenges. Engaging across 70 buildings and their inhabitants, the project captured the evolution of attitudes and intentions towards the clean energy transition in ways directly relevant to future policy implementation across grid redevelopment, smart service design, and national retrofit. Project methodology was framed by a living lab approach, with wireless energy and indoor environment sensors installed in participant buildings and participant journeys developed by harnessing the Citizen Innovation Lab ecosystem. The results indicate behaviour changes among participants, particularly focusing on indoor environmental conditions. The study concludes that embedded, localised living labs offer a methodological framework which can capture diverse datasets and encompass complex contemporary contexts towards transition goals. Full article
(This article belongs to the Special Issue Sustainable Impact and Systemic Change via Living Labs)
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27 pages, 4029 KiB  
Article
Modelling Key Health Indicators from Sensor Data Using Knowledge Graphs and Fuzzy Logic
by Aurora Polo-Rodríguez, Isabel Valenzuela López, Raquel Diaz, Almudena Rivadeneyra, David Gil and Javier Medina-Quero
Electronics 2025, 14(12), 2459; https://doi.org/10.3390/electronics14122459 - 17 Jun 2025
Viewed by 393
Abstract
This paper describes the modelling of Key Health Indicators (KHI) of frail individuals through non-invasive sensors located in their environment and wearable devices. Primary care professionals defined four indicators for daily health monitoring: sleep patterns, excretion control, physical mobility, and caregiver social interaction. [...] Read more.
This paper describes the modelling of Key Health Indicators (KHI) of frail individuals through non-invasive sensors located in their environment and wearable devices. Primary care professionals defined four indicators for daily health monitoring: sleep patterns, excretion control, physical mobility, and caregiver social interaction. A minimally invasive and low-cost sensing architecture was implemented, combining indoor localisation and physical activity tracking through environmental sensors and wrist-worn wearables. The health outcomes are modelled using a knowledge-based framework that integrates knowledge graphs to represent control variables and their relationships with data streams, and fuzzy logic to linguistically define temporal patterns based on expert criteria. The proposed approach was validated in a real-world case study with an older adult living independently in Granada, Spain. Over several days of deployment, the system successfully generated interpretable daily summaries reflecting relevant behavioural patterns, including rest periods, bathroom usage, activity levels, and caregiver proximity. In addition, supervised machine learning models were trained on the indicators derived from the fuzzy logic system, achieving average accuracy and F1 scores of 93% and 92%, respectively. These results confirm the potential of combining expert-informed semantics with data-driven inference to support continuous, explainable health monitoring in ambient assisted living environments. Full article
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22 pages, 8121 KiB  
Article
Field Investigation of Thermal Comfort and Indoor Air Quality Analysis Using a Multi-Zone Approach in a Tropical Hypermarket
by Kathleen Jo Lin Teh, Halim Razali and Chin Haw Lim
Buildings 2025, 15(10), 1677; https://doi.org/10.3390/buildings15101677 - 16 May 2025
Cited by 1 | Viewed by 575
Abstract
Indoor environmental quality (IEQ), encompassing thermal comfort and indoor air quality (IAQ), plays a crucial role in occupant well-being and operational performance. Although widely studied individually, integrating thermal comfort and IAQ assessments remains limited, particularly in large-scale tropical commercial settings. Hypermarkets, characterised by [...] Read more.
Indoor environmental quality (IEQ), encompassing thermal comfort and indoor air quality (IAQ), plays a crucial role in occupant well-being and operational performance. Although widely studied individually, integrating thermal comfort and IAQ assessments remains limited, particularly in large-scale tropical commercial settings. Hypermarkets, characterised by spatial heterogeneity and fluctuating occupancy, present challenges that conventional HVAC systems often fail to manage effectively. This study investigates thermal comfort and IAQ variability in a hypermarket located in Gombak, Malaysia, under tropical rainforest conditions based on the Köppen–Geiger climate classification, a widely used system for classifying the world’s climates. Environmental parameters were monitored using a network of IoT-enabled sensors across five functional zones during actual operations. Thermal indices (PMV, PPD) and IAQ metrics (CO2, TVOC, PM2.5, PM10) were analysed and benchmarked against ASHRAE 55 standards to assess spatial variations and occupant exposure. Results revealed substantial heterogeneity, with the cafeteria zone recording critical discomfort (PPD 93%, CO2 900 ppm, TVOC 1500 ppb) due to localised heat and insufficient ventilation. Meanwhile, the intermediate retail zone maintained near-optimal conditions (PPD 12%). Although findings are specific to this hypermarket, the integrated zone-based monitoring provides empirical insights that support the enhancement of IEQ assessment approaches in tropical commercial spaces. By characterising zone-specific thermal comfort and IAQ profiles, this study contributes valuable knowledge toward developing adaptive, occupant-centred HVAC strategies for complex retail environments in hot-humid climates. Full article
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18 pages, 4659 KiB  
Article
Automated Room-Level Localisation Using Building Plan Information
by Mathias Thorsager, Sune Kroeyer, Adham Taha, Magnus Melgaard, Linette Anil, Jimmy Nielsen and Tatiana Madsen
Sensors 2024, 24(17), 5753; https://doi.org/10.3390/s24175753 - 4 Sep 2024
Viewed by 931
Abstract
Building Management Systems (BMSs) are transitioning from utilising wired installations to wireless Internet of Things (IoT) sensors and actuators. This shift introduces the requirement of robust localisation methods which can link the installed sensors to the correct Control Units (CTUs) which will facilitate [...] Read more.
Building Management Systems (BMSs) are transitioning from utilising wired installations to wireless Internet of Things (IoT) sensors and actuators. This shift introduces the requirement of robust localisation methods which can link the installed sensors to the correct Control Units (CTUs) which will facilitate continued communication. In order to lessen the installation burden on the technicians, the installation process should be made more complicated by the localisation method. We propose an automated version of the fingerprinting-based localisation method which estimates the location of sensors with room-level accuracy. This approach can be used for initialisation and maintenance of BMSs without introducing additional manual labour from the technician installing the sensors. The method is extended to two proposed localisation methods which take advantage of knowledge present in the building plan regarding the distribution of sensors in each room to estimate the location of groups of sensors at the same time. Through tests using a simulation environment based on a Bluetooth-based measurement campaign, the proposed methods showed an improved accuracy from the baseline automated fingerprinting method. The results showed an error rate of 1 in 20 sensors (if the number of sensors per room is known) or as few as 1 per 200 sensors (if a group of sensors are deployed and detected together for one room at a time). Full article
(This article belongs to the Special Issue Sensing Technologies and Wireless Communications for Industrial IoT)
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22 pages, 2674 KiB  
Article
Effect of Using Moisture-Buffering Finishing Materials and DCV Systems on Environmental Comfort and Energy Consumption in Buildings
by Dobrosława Kaczorek and Małgorzata Basińska
Energies 2024, 17(16), 3937; https://doi.org/10.3390/en17163937 - 8 Aug 2024
Viewed by 1344
Abstract
One of the technical solutions to improve indoor thermal comfort and reduce energy consumption in buildings is the use of demand-controlled ventilation (DCV) systems. The choice of the control method becomes more important when the walls in the room are finished with moisture-buffering [...] Read more.
One of the technical solutions to improve indoor thermal comfort and reduce energy consumption in buildings is the use of demand-controlled ventilation (DCV) systems. The choice of the control method becomes more important when the walls in the room are finished with moisture-buffering materials. This study explores the impact of four DCV system control scenarios (control of temperature, relative humidity, and carbon dioxide concentration for two different supply airflows to the room) combined with various indoor moisture-buffering materials (gypsum board and cement–lime plaster) on the variability of indoor air quality parameters, thermal comfort, and energy. The analysis was performed by computer simulation using WUFI Plus v.3.1.0.3 software for whole-building hydrothermal analysis. Control-based systems that maintain appropriate relative humidity levels were found to be the most favourable for localised comfort and were more effective in terms of energy consumption for heating and cooling without humidification and dehumidification. This research also revealed that the moisture-buffering effect of finishing materials can passively contribute to enhancing indoor air quality, regardless of the room’s purpose. However, higher energy consumption for heating was observed for better moisture-buffering materials. Full article
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18 pages, 5430 KiB  
Article
Three-Dimensional Indoor Positioning Scheme for Drone with Fingerprint-Based Deep-Learning Classifier
by Shuzhi Liu, Houjin Lu and Seung-Hoon Hwang
Drones 2024, 8(1), 15; https://doi.org/10.3390/drones8010015 - 9 Jan 2024
Cited by 4 | Viewed by 2900
Abstract
Unmanned aerial vehicles (UAVs) hold significant potential for various indoor applications, such as mapping, surveillance, navigation, and search and rescue operations. However, indoor positioning is a significant challenge for UAVs, owing to the lack of GPS signals and the complexity of indoor environments. [...] Read more.
Unmanned aerial vehicles (UAVs) hold significant potential for various indoor applications, such as mapping, surveillance, navigation, and search and rescue operations. However, indoor positioning is a significant challenge for UAVs, owing to the lack of GPS signals and the complexity of indoor environments. Therefore, this study was aimed at developing a Wi-Fi-based three-dimensional (3D) indoor positioning scheme tailored to time-varying environments, involving human movement and uncertainties in the states of wireless devices. Specifically, we established an innovative 3D indoor positioning system to meet the localisation demands of UAVs in indoor environments. A 3D indoor positioning database was developed using a deep-learning classifier, enabling 3D indoor positioning through Wi-Fi technology. Additionally, through a pioneering integration of fingerprint recognition into wireless positioning technology, we enhanced the precision and reliability of indoor positioning through a detailed analysis and learning process of Wi-Fi signal features. Two test cases (Cases 1 and 2) were designed with positioning height intervals of 0.5 m and 0.8 m, respectively, corresponding to the height of the test scene for positioning simulation and testing. With an error margin of 4 m, the simulation accuracies for the (X, Y) dimension reached 94.08% (Case 1) and 94.95% (Case 2). When the error margin was 0 m, the highest simulation accuracies for the H dimension were 91.84% (Case 1) and 93.61% (Case 2). Moreover, 40 real-time positioning experiments were conducted in the (X, Y, H) dimension. In Case 1, the average positioning success rates were 50.8% (Margin-0), 72.9% (Margin-1), and 81.4% (Margin-2), and the corresponding values for Case 2 were 52.4%, 74.5%, and 82.8%, respectively. The results demonstrated that the proposed method can facilitate 3D indoor positioning based only on Wi-Fi technologies. Full article
(This article belongs to the Special Issue Drones Navigation and Orientation)
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30 pages, 10429 KiB  
Article
A High-Accuracy, Scalable and Affordable Indoor Positioning System Using Visible Light Positioning for Automated Guided Vehicles
by Aleix Boixader, Carlos Labella, Marisa Catalan and Josep Paradells
Electronics 2024, 13(1), 82; https://doi.org/10.3390/electronics13010082 - 23 Dec 2023
Cited by 2 | Viewed by 2705
Abstract
Indoor Positioning Systems (IPSs) have multiple applications. For example, they can be used to guide people, to locate items in a warehouse and to support the navigation of Automated Guided Vehicles (AGV). Currently most AGVs use local pre-defined navigation systems, but they lack [...] Read more.
Indoor Positioning Systems (IPSs) have multiple applications. For example, they can be used to guide people, to locate items in a warehouse and to support the navigation of Automated Guided Vehicles (AGV). Currently most AGVs use local pre-defined navigation systems, but they lack a global localisation system. Integrating both systems is uncommon due to the inherent challenge in balancing accuracy with coverage. Visible Light Position (VLP) offers accurate and fast localisation, but it encounters scalability limitations. To overcome this, this paper presents a novel Image Sensor-based VLP (IS-VLP) identification method that harnesses existing Light Emitting Diode (LED) lighting infrastructure to substitute both navigation and localisation systems effectively in the whole area. We developed an IPS that achieves six-axis positioning at 90 Hz refresh rate using OpenCV’s solvePnP algorithm and embedded computing. This IPS has been validated in a laboratory environment and successfully deployed in a real factory to position an operative AGV. The system has resulted in accuracies better than 12 cm for 95% of the measurements. This work advances towards positioning VLP as an appealing choice for IPS in industrial environments, offering an inexpensive, scalable, accurate and robust solution. Full article
(This article belongs to the Special Issue Advances in Radio, Visible Light Communications, and Fiber Optics)
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19 pages, 5509 KiB  
Article
A Multi-Sensor Fusion Approach Based on PIR and Ultrasonic Sensors Installed on a Robot to Localise People in Indoor Environments
by Ilaria Ciuffreda, Sara Casaccia and Gian Marco Revel
Sensors 2023, 23(15), 6963; https://doi.org/10.3390/s23156963 - 5 Aug 2023
Cited by 14 | Viewed by 4470
Abstract
This work illustrates an innovative localisation sensor network that uses multiple PIR and ultrasonic sensors installed on a mobile social robot to localise occupants in indoor environments. The system presented aims to measure movement direction and distance to reconstruct the movement of a [...] Read more.
This work illustrates an innovative localisation sensor network that uses multiple PIR and ultrasonic sensors installed on a mobile social robot to localise occupants in indoor environments. The system presented aims to measure movement direction and distance to reconstruct the movement of a person in an indoor environment by using sensor activation strategies and data processing techniques. The data collected are then analysed using both a supervised (Decision Tree) and an unsupervised (K-Means) machine learning algorithm to extract the direction and distance of occupant movement from the measurement system, respectively. Tests in a controlled environment have been conducted to assess the accuracy of the methodology when multiple PIR and ultrasonic sensor systems are used. In addition, a qualitative evaluation of the system’s ability to reconstruct the movement of the occupant has been performed. The system proposed can reconstruct the direction of an occupant with an accuracy of 70.7% and uncertainty in distance measurement of 6.7%. Full article
(This article belongs to the Special Issue Metrology for Living Environment)
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19 pages, 6096 KiB  
Article
ROS-Based Autonomous Navigation Robot Platform with Stepping Motor
by Shengmin Zhao and Seung-Hoon Hwang
Sensors 2023, 23(7), 3648; https://doi.org/10.3390/s23073648 - 31 Mar 2023
Cited by 11 | Viewed by 7929
Abstract
Indoor navigation robots, which have been developed using a robot operating system, typically use a direct current motor as a motion actuator. Their control algorithm is generally complex and requires the cooperation of sensors such as wheel encoders to correct errors. For this [...] Read more.
Indoor navigation robots, which have been developed using a robot operating system, typically use a direct current motor as a motion actuator. Their control algorithm is generally complex and requires the cooperation of sensors such as wheel encoders to correct errors. For this study, an autonomous navigation robot platform named Owlbot was designed, which is equipped with a stepping motor as a mobile actuator. In addition, a stepping motor control algorithm was developed using polynomial equations, which can effectively convert speed instructions to generate control signals for accurately operating the motor. Using 2D LiDAR and an inertial measurement unit as the primary sensors, simultaneous localization, mapping, and autonomous navigation are realised based on the particle filtering mapping algorithm. The experimental results show that Owlbot can effectively map the unknown environment and realise autonomous navigation through the proposed control algorithm, with a maximum movement error being smaller than 0.015 m. Full article
(This article belongs to the Special Issue Mobile Robots for Navigation)
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22 pages, 6060 KiB  
Article
Real-Time Location System (RTLS) Based on the Bluetooth Technology for Internal Logistics
by Augustyn Lorenc, Jakub Szarata and Michał Czuba
Sustainability 2023, 15(6), 4976; https://doi.org/10.3390/su15064976 - 10 Mar 2023
Cited by 11 | Viewed by 3931
Abstract
The problem of object localization in indoor environments is very important in order to make a company effective and to detect disruption in the logistics system in real-time. Present research investigates how the IoT (Internet of Things) location system based on Bluetooth can [...] Read more.
The problem of object localization in indoor environments is very important in order to make a company effective and to detect disruption in the logistics system in real-time. Present research investigates how the IoT (Internet of Things) location system based on Bluetooth can be implemented for this solution. The location based on the Bluetooth is hard to predict. Radio wave interference in this frequency is affected by other devices, steel, vessels containing water, and more. However, proper data processing and signal stabilization can increase the accuracy of the location. To be sure that the location system based on the BT (Bluetooth) can be implemented for real cases, an analysis of signal strength amplitude and disruption was made. The paper presents R&D (Research and Development) works with a practical test in real cases. The signal strength fluctuation for the receiver is between 7 and 10 dBm for ESP32 device and between 13 and 14 dBm for Raspberry. For commercial implementation the number of devices scanned in the time window is also important. For Raspberry, the optimal time window is 5 s; in this time six transmitters can be detected. ESP32 has a problem with detecting devices in a short time, as just two transmitters can be detected in 4–8 s time window. Localisation precision depends on the distance between transmitter and receiver, and the angle from the axis of the directional antenna. For the distance of 10 m the measurement error is 1.2–6.1 m, whilst for the distance of 40 m the measurement error is 4.9 to 24.6 m. Using a Kalman filter can reduce the localization error to 1.5 m. Full article
(This article belongs to the Special Issue Industry 4.0 and Artificial Intelligence for Resilient Supply Chains)
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33 pages, 32293 KiB  
Article
New Tools for Urban Analysis: A SLAM-Based Research in Venice
by Beatrice Tanduo, Andrea Martino, Caterina Balletti and Francesco Guerra
Remote Sens. 2022, 14(17), 4325; https://doi.org/10.3390/rs14174325 - 1 Sep 2022
Cited by 10 | Viewed by 2769
Abstract
This research proposes a detailed analysis of the potential of MMS (Mobile Mapping Systems), supported by SLAM (Simultaneous Localisation And Mapping) algorithms, performed on a multiscale test field in order to make a concrete contribution to the morphological study of cities. These systems, [...] Read more.
This research proposes a detailed analysis of the potential of MMS (Mobile Mapping Systems), supported by SLAM (Simultaneous Localisation And Mapping) algorithms, performed on a multiscale test field in order to make a concrete contribution to the morphological study of cities. These systems, developed with the aim of acquiring a large number of points in a short time, are able to map the surrounding area and automatically localise themselves in real time in relation to a determined reference system. The analysed area, located in Venice, was divided into three different test fields characterised by typical elements potentially comparable to those of other urban realities. The data were acquired using the LiBackPack C50, Kaarta Stencil and Heron Lite systems and compared quantitatively and qualitatively with data obtained from more traditional surveying techniques. Specifically, the data obtained from TLS (Terrestrial Laser Scanning) surveys, supported by topographic measurements, were the most accurate basis on which to evaluate the accuracy and completeness of the three different MMS devices. The standard deviation values were initially analysed in the final 3D global models using the C2C (Cloud to Cloud) and C2M (Cloud to Mesh) distance calculation methods. Subsequently, the geometric differences were investigated through the extraction of horizontal profiles, and two more specific 2D analyses were carried out: the first inspecting the residual parameters calculated after the Helmert transformation from two sets of control points obtained from the profiles, followed by a local strain analysis. The study of the local deformation parameters allowed us to validate the results obtained and to identify the real limits of these survey instruments. The aim was to make a concrete contribution to the formalisation of an operative protocol for the morphological study of the city, exploiting the potential of these technologies to overcome the differences in scale and the gap between outdoor and indoor spaces. Full article
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45 pages, 799 KiB  
Systematic Review
Cloud Platforms for Context-Adaptive Positioning and Localisation in GNSS-Denied Scenarios—A Systematic Review
by Darwin Quezada-Gaibor, Joaquín Torres-Sospedra, Jari Nurmi, Yevgeni Koucheryavy and Joaquín Huerta
Sensors 2022, 22(1), 110; https://doi.org/10.3390/s22010110 - 24 Dec 2021
Cited by 11 | Viewed by 4461
Abstract
Cloud Computing and Cloud Platforms have become an essential resource for businesses, due to their advanced capabilities, performance, and functionalities. Data redundancy, scalability, and security, are among the key features offered by cloud platforms. Location-Based Services (LBS) often exploit cloud platforms to host [...] Read more.
Cloud Computing and Cloud Platforms have become an essential resource for businesses, due to their advanced capabilities, performance, and functionalities. Data redundancy, scalability, and security, are among the key features offered by cloud platforms. Location-Based Services (LBS) often exploit cloud platforms to host positioning and localisation systems. This paper introduces a systematic review of current positioning platforms for GNSS-denied scenarios. We have undertaken a comprehensive analysis of each component of the positioning and localisation systems, including techniques, protocols, standards, and cloud services used in the state-of-the-art deployments. Furthermore, this paper identifies the limitations of existing solutions, outlining shortcomings in areas that are rarely subjected to scrutiny in existing reviews of indoor positioning, such as computing paradigms, privacy, and fault tolerance. We then examine contributions in the areas of efficient computation, interoperability, positioning, and localisation. Finally, we provide a brief discussion concerning the challenges for cloud platforms based on GNSS-denied scenarios. Full article
(This article belongs to the Special Issue Applications and Innovations on Sensor-Enabled Wearable Devices)
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17 pages, 1378 KiB  
Article
WiFi FTM, UWB and Cellular-Based Radio Fusion for Indoor Positioning
by Carlos S. Álvarez-Merino, Hao Qiang Luo-Chen, Emil Jatib Khatib and Raquel Barco
Sensors 2021, 21(21), 7020; https://doi.org/10.3390/s21217020 - 23 Oct 2021
Cited by 29 | Viewed by 4499
Abstract
High-precision indoor localisation is becoming a necessity with novel location-based services that are emerging around 5G. The deployment of high-precision indoor location technologies is usually costly due to the high density of reference points. In this work, we propose the opportunistic fusion of [...] Read more.
High-precision indoor localisation is becoming a necessity with novel location-based services that are emerging around 5G. The deployment of high-precision indoor location technologies is usually costly due to the high density of reference points. In this work, we propose the opportunistic fusion of several different technologies, such as ultra-wide band (UWB) and WiFi fine-time measurement (FTM), in order to improve the performance of location. We also propose the use of fusion with cellular networks, such as LTE, to complement these technologies where the number of reference points is under-determined, increasing the availability of the location service. Maximum likelihood estimation (MLE) is presented to weight the different reference points to eliminate outliers, and several searching methods are presented and evaluated for the localisation algorithm. An experimental setup is used to validate the presented system, using UWB and WiFi FTM due to their incorporation in the latest flagship smartphones. It is shown that the use of multi-technology fusion in trilateration algorithm remarkably optimises the precise coverage area. In addition, it reduces the positioning error by over-determining the positioning problem. This technique reduces the costs of any network deployment oriented to location services, since a reduced number of reference points from each technology is required. Full article
(This article belongs to the Special Issue Indoor Wi-Fi Positioning: Techniques and Systems)
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25 pages, 7595 KiB  
Article
Automated Calibration of RSS Fingerprinting Based Systems Using a Mobile Robot and Machine Learning
by Marcin Kolakowski
Sensors 2021, 21(18), 6270; https://doi.org/10.3390/s21186270 - 18 Sep 2021
Cited by 11 | Viewed by 3715
Abstract
This paper describes an automated method for the calibration of RSS-fingerprinting-based positioning systems. The method assumes using a robotic platform to gather fingerprints in the system environment and using them for training machine learning models. The obtained models are used for positioning purposes [...] Read more.
This paper describes an automated method for the calibration of RSS-fingerprinting-based positioning systems. The method assumes using a robotic platform to gather fingerprints in the system environment and using them for training machine learning models. The obtained models are used for positioning purposes during the system operation. The presented calibration method covers all steps of the system calibration, from mapping the system environment using a GraphSLAM based algorithm to training models for radio map calibration. The study analyses four different models: fitting a log-distance path loss model, Gaussian Process Regression, Artificial Neural Network and Random Forest Regression. The proposed method was tested in a BLE-based indoor localisation system set up in a fully furnished apartment. The results have shown that the tested models allow for localisation with accuracy comparable to those reported in the literature. In the case of the Neural Network regression, the median error of robot positioning was 0.87 m. The median of trajectory error in a walking person localisation scenario was 0.4 m. Full article
(This article belongs to the Special Issue Indoor–Outdoor Seamless Navigation for Mass-Market Devices)
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29 pages, 8598 KiB  
Article
Landmark-Assisted Compensation of User’s Body Shadowing on RSSI for Improved Indoor Localisation with Chest-Mounted Wearable Device
by Md Abdulla Al Mamun, David Vera Anaya, Fan Wu and Mehmet Rasit Yuce
Sensors 2021, 21(16), 5405; https://doi.org/10.3390/s21165405 - 10 Aug 2021
Cited by 4 | Viewed by 3595
Abstract
Nowadays, location awareness becomes the key to numerous Internet of Things (IoT) applications. Among the various methods for indoor localisation, received signal strength indicator (RSSI)-based fingerprinting attracts massive attention. However, the RSSI fingerprinting method is susceptible to lower accuracies because of the disturbance [...] Read more.
Nowadays, location awareness becomes the key to numerous Internet of Things (IoT) applications. Among the various methods for indoor localisation, received signal strength indicator (RSSI)-based fingerprinting attracts massive attention. However, the RSSI fingerprinting method is susceptible to lower accuracies because of the disturbance triggered by various factors from the indoors that influence the link quality of radio signals. Localisation using body-mounted wearable devices introduces an additional source of error when calculating the RSSI, leading to the deterioration of localisation performance. The broad aim of this study is to mitigate the user’s body shadowing effect on RSSI to improve localisation accuracy. Firstly, this study examines the effect of the user’s body on RSSI. Then, an angle estimation method is proposed by leveraging the concept of landmark. For precise identification of landmarks, an inertial measurement unit (IMU)-aided decision tree-based motion mode classifier is implemented. After that, a compensation model is proposed to correct the RSSI. Finally, the unknown location is estimated using the nearest neighbour method. Results demonstrated that the proposed system can significantly improve the localisation accuracy, where a median localisation accuracy of 1.46 m is achieved after compensating the body effect, which is 2.68 m before the compensation using the classical K-nearest neighbour method. Moreover, the proposed system noticeably outperformed others when comparing its performance with two other related works. The median accuracy is further improved to 0.74 m by applying a proposed weighted K-nearest neighbour algorithm. Full article
(This article belongs to the Special Issue Wireless Sensing and Networking for the Internet of Things)
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